Valeur qui disparait

<div id="FAVOREE_content"/><script type="text/javascript">	///////////////////////////////////	// Class "Item"	///////////////////////////////////	function Item(unique, depth)	{		this.id = unique;		this.depth = depth;		this.caption = "";	}	Item.prototype.Import = function(str)	{		this.caption = str;		alert('ECRITURE : caption = "' + this.caption + '"');	};	Item.prototype.to_HTML = null;	///////////////////////////////////	// Class "Favori" extends "Item"	///////////////////////////////////	Favori.prototype = new Item();	Favori.prototype.constructor = Favori;	function Favori(unique, depth)	{		Item.call(this, unique, depth);		this.url = "";	}	Favori.prototype.Import = function(str)	{		Item.prototype.Import("Yahoo");		alert('APRES ECRITURE : Favori.caption = "' + this.caption + '"');		this.url = "www.yahoo.fr"	};	Favori.prototype.to_HTML = function()	{		alert('Lecture Favori.caption = "' + this.caption + '"');	};	///////////////////////////////////	// Class "Folder" extends "Item"	///////////////////////////////////	Folder.prototype = new Item();	Folder.prototype.constructor = Folder;	function Folder(unique, depth)	{		Item.call(this, unique, depth);		this.children = new Array;	}	Folder.prototype.Import = function(str)	{		Item.prototype.Import(str);		alert('APRES ECRITURE : Folder.caption = "' + this.caption + '"');		var favori = new Favori(this.unique + "_1", this.depth + 1);		favori.Import("Yahoo");		this.children.push(favori);	};	Folder.prototype.to_HTML = function()	{		alert('Lecture Folder.caption = "' + this.caption + '"');		this.children[0].to_HTML();	};	var root = new Folder("item", 0);	root.Import("Root"); // Va creer les valeurs	root.to_HTML();      // va les lire, et les valeur aurotn disparu !</script>